Never. The purpose of ai is to support human intelligence and make it super efficient and not to replace it. Since areas where our brain is not that strong, machines could do it super easy. As a simple example, take the case of multiplication of two large numbers, the machine can do it very fast but not that easy for the brain. Another case of identifying a picture to see who is in the picture. This task is very easy for the brain but tedious for machines.
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